Advertisement
Baltimore Sun

Big Indonesian quake rattles Virginia well

This morning's big 7.5 earthquake in Indonesia sent ripples through the Earth's crust and around the planet. When they got to the USGS monitoring well in Christiansburg, Va., they sent the water levels sloshing up and down.

You can see the impact on the graph above - evident in the sharp peaks at the top of the last curve on the chart.

Advertisement

This response is not unusual for this well, which is extraordinarily sensitive to seismic waves racing through the planet's rocky crust. Here's a list of previous quakes that have set off the Christiansburg well.

The longer, and quite regular wave-like cycles on the graph of water levels in the well are the result of the moon's gravity, which affects the Earth's rocky crust in much the same way as it affects the oceans. You can't see it in the rocks, but these tidal effects in the rocks can be seen easily in their effects on the aquifers - the water contained within cracks in the bedrock. That's what the graph shows.

Advertisement

Cool, huh?

Earthquakes have also been known to cause another type of sloshing effect in bodies of water and swimming pools hundreds or even thousands of miles from the quake's epicenter. They're called seismic seiches. Here's more.


Advertisement